Several iPhone users including those with iPhone 6 and 6 Plus are complaining about an unusual battery drain on their respective devices especially after getting the iOS 9 beta software update. If you happen to be one of them and that you bumped into this site in search for potential solutions, then you can try any of the quick battery drain workarounds highlighted in this post.

Note: The methods we introduced in this content are generic solutions to a problem on quick battery drain and are therefore applicable to any other iOS devices having similar issue.

1. Give your device enough time to process everything.

Given the file size and embedded features into the newly released iOS updates, it's normal for any receiving device to use a lot of power at first. This is the same case when you perform system restores on any device. During the process, lot of files are moved around, libraries are updated, and contents re-indexed, in order to get everything set up. All these can keep your device's processor busy, as apps are likewise updating and your Wi-Fi or cellular connection blasting. That being said, give your iPhone some time to perform all these processes and after that you should be fine. Otherwise, continue with the following workarounds.

2. Check which app(s) consumes a lot of your phone's battery life.

Your device comes with power-management interface wherein you can view which applications/processes are using a lot of the battery power.

To access this menu, navigate to your iPhone Settings-> General -> Usage -> Usage -> Battery Usage. There you can find a list of applications and systems, along with the amount of power they've used up for certain period of time.

If you see something unusual, then you can try to force close (double-tap the Home button and flick the app up and away), disable the culprit temporarily or uninstall it if necessary. Don't forget to reboot your device afterwards.

3. Ensure your iPhone has strong cell signal.
Try to check your cell signal and see if you're getting LTE service. Getting poor LTE signal could also cause your phone's battery to drain so quick as it triggers your device to switch between connection/network types, thereby wasting a lot of power. If you're in an area with weak signal or at the edge of LTE, then switch to 3G. But if you're almost off the grid, then you should disable the radio unless you need it.

4. Adjust some device settings.

Screen brightness, type of wallpaper used, as well as running apps and some active phone features including Wi-Fi, Bluetooth, and GPS, can also trigger quick battery draining issue on any iOS device. And for these reasons, proper configuration of these settings is recommended.
Try to reduce your screen brightness, and disable the aforesaid features especially when not in use.

If the problem persists or your iPhone 6 battery keeps draining so fast even after performing the previous methods, please contact your phone carrier or Apple Support for further recommendations. Otherwise, you may need to consider replacing the battery this time.